Table 5. The recoveries after each unit operation for the six downstream processes, based on total protein (tot.protein) and HA quantities, relative to the fraction after zonal ultracentrifugation (Fig 1, fraction 2.1F and 2.1B).

Noteworthy is the difference in HA recovery versus total protein recovery after sterile filtration of the ether split formaldehyde inactivated product FE: 32% versus 72% in product 5.1 after SF, which cannot be attributed to the test variation of 7.5% for total protein and 20% for SRID test.

Formaldehyde inactivated products		ether split virus		whole virus		Triton split virus
		FE	FE	F	F	FT	FT
		tot.protein	HA	tot.protein	HA	tot.protein	HA
description	fraction	%	%	%	%	%	%
after zonal	2.1	100%	100%	100%	100%	100%	100%
after inactivation	2.2	Na	na	115%	95%	115%	95%
after DF	3.0, 3.1	87%	86%	93%	104%	93%	104%
after split	3.3	94%	96%	na	na	70%	85%
after SF	5.1	72%	32%	52%	49%	49%	72%
Total of all unit operations		58%	27%	56%	49%	36%	60%
Beta-PropioLactone inactivated products		ether split virus		whole virus		Triton split virus
		BE	BE	B	B	BT	BT
		tot.protein	HA	tot.protein	HA	tot.protein	HA
description	fraction	%	%	%	%	%	%
after zonal	2.1	100%	100%	100%	100%	100%	100%
after inactivation	2.2	103%	103%	103%	103%	103%	103%
after DF	3.0, 3.1	100%	102%	100%	102%	100%	102%
after split	3.3	68%	85%	na	na	77%	91%
after SF	5.1	84%	90%	69%	71%	52%	67%
Total of all unit operations		58%	81%	71%	74%	41%	64%

The upper part of the table presents all processes using formaldehyde inactivation, the lower part presents all processes including BPL inactivation. The fraction numbers relate to the phase after a unit operation (Fig 1).

na: not applicable (Fig 1). “Total of all unit operations” is the final recovery result after all unit operations of the downstream process starting from the zonal centrifugation fraction at 100%

DF: diafiltration

SF: sterile filtration